New approach for controlling tight hole in salt formation

The conventional approach to avoid stuck in salt formation is to use high density saturated brine mud. This approach may be effectual in some low in-situ stress and low temperature salt formation, but can not prevent from tight hole in high in-situ stress and high temperature salt formation. In addition, it is impractical to increase mud weight too much in drilling practice because mud lost may be induced in weak sand. A new way is presented to control tight hole in high in-situ stress and high temperature salt formation by low density unsaturated brine mud. The salt solution rate can be controlled by adjusting content. If the balance between salt solution rate and hole shrinkage rate is established, stuck can be avoided successfully. The technique is used successfully in field.